Nuts & Bolts - SEO: Is HTTP or HTTPS Better for SEO?

Just two days after the Wall Street Journal quoted Matt Cutts, the head of Google’s Webspam team, as saying marketers with encrypted sites may see a boost in search engine rankings, San Diego-based search marketing agency Covario weighed in with its point of view. This is still a “maybe,” but marketers should be proactive about it and switch from HTTP to HTTPS, says Covario’s SEO Manager Michael Martin.

“If webmasters are able to provide adequate security processing of search engine referrals, this would shield Google from legal ramifications related to user data breaches,” Martin wrote on April 16. “Consequently, Google would reward more trusted websites with improvements in rankings, as well as provide additional insights into organic search referral data, including keyword details.”

In his paper, “Security Being a Search Advantage,” Martin emphasizes marketers should add transport layer security (TLS) onto their HTTP to create HTTPS, rather than the “outdated” TLS predecessor, secure sockets layer (SSL). The latest version of TLS will help marketers avoid the “Heartbleed” exploit, he says.
Martin believes marketers should be proactive because:

This is a blanket statement that could have unintended negative consequences.
There is overhead to https transfers that can slow down the connection and increase the time to render the web page.
Slower page loads will affect your SEO in two ways. Google will notice slower page loading and adjust your ranking accordingly. Visitors will notice your page load speed and some will not wait.
If you are going to use https, only use it where you need it. Only use it when security critical data is being passed or stored.